Turns Played (this run): 1,695
Days Played (this run): 12
Definitely worth taking the challenge path. I actually could've done it a bit faster, but I did a 100% familiar run as well (haven't done 5 of them yet).
The war is a pain in the ass though... you'll be losing 40% HP per fight, 125ish times.
My class was Pastamancer if you're wondering. The biggest issue I ran into was that it's basically impossible to get a hardcore chef staff with no B's involved. This made the level 9 and 10 areas very hard until I got Noodles of Fire.
